Evaluation of Different Extracting Methods of Inorganic Solutes (Na, K & Ca) Determination in Wheat for Salinity Screening Programs

Abstract

A detailed study was conducted to compare different extraction/ digestion methods (Solute extraction by water (cold and hot), Solute extraction by weak acid (Acetic acid,CH3COOH), Solute extraction by organic solvent (toluene), direct total analysis by wet oxidation (H2SO4, H2O2) and direct total analysis by wet oxidation (HClO4 : HNO3) in 1:5 ratio), for determination of inorganic solutes especially (Na, K and Ca), to select most suitable, accurate efficient, and economical analytical methods for ionic analysis for smooth running of salt screening programs. Wheat crop was selected as test crop under saline and non-saline environments to observe the effect of genotypic and environmental variability on extracting methods. It was observed that there is wide variation in ionic contents among the extraction/ digestion methods. It was also observed that the determination of inorganic solutes especially (Na, K and Ca), by extracting method with 0.5% toluene water is highly correlated with wet digestion either by Nitric per chloric acid (HClO4: HNO3) in 1:5 ratio or sulphuric acid and hydrogen per oxide (H2SO4, H2O2). The extraction with 0.5% toluene water is safe, economical and efficient, therefore it is highly recommended to adopt the Solute extraction by organic solvent (toluene) method for salinity screening programs.